Mr Patel, 67, filed his papers today for an fifth consecutive term as an MP of the Upper House. He told NDTV that he has met Mr Vagehla, who has assured him of support. "There is no reason not to believe him," Mr Patel said.

Mr Vaghela too confirmed that he will honour an earlier promise to support Ahmed Patel but added a rider - Ashok Gehlot, the Congress leader in charge of Gujarat, must withdraw his comments on his exit from the party. Mr Gehlot said yesterday that Mr Vaghela seemed to have quit the Congress for fear that the ruling BJP would use central investigation agencies to pursue an old corruption case against him.

"This is character assassination. The case is closed. I am daring Gehlot to get the case re-opened. My public life is transparent," Mr Vagehla said today.

Last week 11 members of the Congress, believed to be Mr Vaghela's loyalists, rebelled against the party and voted for Ram Nath Kovind as President of India. The Congress, along with 17 other parties, had chosen Meira Kumar as its nominee. The cross-voting was seen as a signal that Mr Vagehla can play spoiler in crucial elections for the Congress- like the election of Mr Patel, which will take place on August 8.

In Gujarat, where elections will be held for three seats, the BJP will win two with ease and intends to field a third candidate too - with Mr Vagehla's covert support, this could endanger Mr Patel's chances. In addition to this being a prestige point, Mr Patel's defeat could dent Congress morale at a time when the BJP chief Amit Shah is leading a vigorous campaign committed to improving the party's hold on Gujarat, which it has governed for nearly two decades. Mr Vaghela has denied that he has joined hands with the BJP for the Rajya Sabha election.

Mr Vagehla, a north Gujarat heavyweight and a former BJP man, has said he will not rejoin his old party now that the Congress has cut him loose -though both his son and he remain Congress members of the legislature.

The Congress has 57 MLAs in the 182-seat Gujarat Assembly. It needs the support of 47 for its candidate to win. If the same 11 vote against Mr Patel, he could be in trouble. But Sharad Pawar's NCP and Nitish Kumar's JD(U) have reportedly offered the support of three members. Even if that happens, it's a close call.

The Congress has warned its legislators that any cross voting in the Rajya Sabha elections will invite disqualification for six years from the party. Unlike voting for President, Rajya Sabha elections have an open ballot -which means votes are easily identifiable.

Gujarat's BJP unit met yesterday and has sent names of possible candidates for the three Rajya Sabha seats for the party's central leaders to consider. Union Textile Minister Smriti Irani, who has also been handed charge of the Information and Broadcasting Ministry, holds one of the seats. Her term, like that of the BJP's Dilip Pandya and Mr Patel, ends on August 18.